Apparatus for manufacturing concrete pipes



June 30, 1942. E. F. BESPALOW 2,287,853

' APPARATUS FOR MANUFACTURING GONCRETEPIPES Filed July 23, 1941 lllll Ill/L n Patented June 30, 1942 7 APPAnATUs FOR MANUFACTURING CONCRETE PIPES Application July 23, 1941', Serial No. 403,726

6 Claims.

More particularly the present invention relates to the production of molded concrete pipes employed in subsoil drainage, the invention having for its general aim the manufacture of such drainage pipes with perforations, formed during the molding operation, in the upper side of the pipe to permit the drainage water to enter the pipe, the lower half of the pipe remaining imperforate to carry off the drainage water. When desired, the perforations may be in the lower half of the pipe or all around the pipe.

It is therefore the aim and object of the present invention to provide a form or mold for the casting of concrete pipe, the form having apertures suitably arranged and disposed, and pins carried by the form adapted for projection into the interior of the form and for retraction after the perforations in the wall of the pipe have been formed and before the concrete has set.

The pins are preferably carried in gangs by bars disposed longitudinally of the form. Springs are desirably associated with each bar which normally hold the bars and pins in retracted position and manually operable cam means are also carried by the form to project the pins through the apertures in the form against the springs. The springs are disposed between the bars and the outer face of the form and are desirably carried by some of the pins while other pins carry stop means which engage the outer face of the form to limit the movement of the pins interiorly of the form.

The present form is particularly applicable in the method in which only a form for the exterior surface of the pipe is employed, the interior surface of the pipe being formed by a plunger or ram having a rotatable packer head disposed interiorly of the form and which also moves upwardly lengthwise of the form as the concrete is being delivered, thereby packing the concrete tightly against the interior wallof the form. In the present method the pipe may be formed in the customary manner and before the form is released from the pipe, the pins are projected through the wall and immediately retracted, the perforations being thus formed by this operation. As an alternative method the pins may be projected into the form prior to the feeding of the concrete and the latter thus is packed against the side Walls of the form and around the pins. When the pipe is thus formed, the pins are retracted, the form released and the concrete allowed to set.

Other objects and advantages of the present invention will be apparent to persons skilled in the art from the following specification and the accompanying drawing.

Fig. 1 is a longitudinal sectional View of the apparatus embodying my invention and employed in practicing my improved-method;

Fig. 2 is a transverse sectional view of the form taken on line 2-2 in Fig. 1;

Fig. 3 is an enlarged fragmentary view of the form showing the pins in projected position;

Fig. 4 is a View similar to Fig. 3 with the pins in retracted position;

Fig. 5 is a transverse sectional view of a concrete pipe formed by the present method and apparatus.

The form of the present invention comprises two longitudinal mating halves l0 and H, each having a bell-shaped end" l2, it being understood that when desired, as when straight ended pipes are made, the forms have no bell-shaped ends, and are straight ended. The two halves are held together when in use by the clamps l3. The semi-cylindrical forms [8 and H may be made of sheet metal and, as shown, may have annular grooves or corrugations l4 so as to impart to the pipe a corrugated exterior face.

The drainage pipe 32 formed by the present method and apparatus has perforations in only the upper half of the pipe so as to permit surface moisture to enter the pipe. Only half of the form or mold, therefore, needs to be provided with perforation forming pins. Thus the pins may be carried by the adjacent portions of the two halves In and II or, as shown, the pins may all be carried by the half I I. When desired such perforations may be provided in the lower half or all around the pipe and for the latter purpose both halves of the form or mold are provided with perforation forming pins. For this purpose the form II has several vertical rows of apertures, which are preferably disposed in the crowns of the corrugations, although they may be disposed in any suitable'manner. Fixedly mounted on the exterior face of the form H are several suitably disposed 'U-shaped yokes It? with their bottoms afiixed to the form, as by welding, and the legs extending outwardly from the form II. The free ends of the yoke are bridged by the bolt IT. A manually operable cam device it,

is oarried'by each bolt and is rotatable on the bolt [1 orwith it in the apertured ends of the yoke I6. The cam device (8 has a handle I!) and a cam head 2-6 disposed between the legs of the yoke l6.

Several bars 2|, each somewhat shorter than the length of the form, are disposed longitudinally of the form, one within each of the yokes I6, so that it overlies a vertical row of apertures I5. Each bar carries a gang of pins 23 in registry with the apertures I5 in the form. Some of the pins carry helical springs 22 between the bar and the form, which serve to hold the bars and pins in the normally retracted position when the cams 18 are in released position. In this position the free ends of the pins extend into the perforations I5 of the form, but preferably do not project to any substantial extent into the/interior of the form. When the cam device is moved to the position shown in Figure 3, the bar 2i, together with the pins carried thereby, is moved against the action of the springs 22 and the pins are projected into the interior of the form. Some of the pins 23 and preferably the end ones in each gang carry adjustable nuts 2'4 which serve as stops for the inward movement of the bar and pins,

In operation the two complemental form sections H) and l I are secured together by the clamp I3, and the form thus obtained is now employed in a suitable machine generally illustrated in Fig. 1. The bell-shaped end I2 of the form is placed on the support 25 and the form is retained thereon against rotation by the interengagement of the lug or lugs 26 with a suitable recess in the table 25. A similar arrangement is provided at the top of the form. A suitably shaped rotatable block 21 having a maximum external diameter smaller than the internal diameter of the form serves to form the shouldered end flange at the bell-shaped end of the concrete pipe. The machine is also provided with a rotatable reciprocating ram or packer head 28 carried by the shaft 29 by means of the coupling 30. The packer head 28 is provided on its upper face with suitably shaped blades 3i which operate to throw outwardly against the inner face of the form the concrete which is fed into the path of these blades.

The packer head 28 is moved downwardly into the central opening in the block 21. The cams 20 are moved to the position shown in Fig. 3, thereby forcing the bars 2| against the springs 22 and projecting the pins 23 into the interior of the form.

The concrete mix is now poured into the form at the proper rate and at the same time the block 2'! and the packer head 28 are rotated. The concrete mix employed in this method contains an adequate amount of water for setting the con crete, the mix, however, being relatively dry. As the concrete is being fed into the form the packer head 28 is gradually withdrawn upwardly. The blades 3| throw the concrete against the form and the concrete is packed tightly in the annular space between the packer head and the form as the packer head moves upwardly.

The pins 23 projecting inwardly of the form the full thickness of the wall of the pipe, the concrete is packed around the pins. The packer head 28 and its blades 3| scrape lightly against the free ends of the pins. The bars 2| are preferably rigid and hold the pins extended into the form the full thickness of the wall of the pipe, and thereby serve to form perforations that extend all the way through the wall. The packer head 28 is operated through a bearing which permits slight lateral movement of the packer head, thus obviating all possibility of jamming.

When the packing operation is completed and the packer head is free of the form, the form with the concrete pipe within it is removed from the machine, the cams l8 are moved to the position shown in Fig. 2, and the springs 22 cause the retraction of the pins from the concrete. The sections In and I I of the form are then uncoupled and removed from the formed apertured pipe. The concrete mix employed is sufficiently dry so that the pipe is self supporting as soon as formed, and the form is free for immediate use on another pipe.

If desired the packing may be conducted with the pins in retracted position and then immediately upon the completion of the packing or forming operation the cams I8 may be operated to project the pins through the walls of the formed pipe and immediately retracted.

The present invention, it will be understood, facilitates the perforation of concrete pipes without causing any deformation in the walls of the pipe.

The present specification and the accompanying drawing illustrate a preferred embodiment of the invention; it will be understood, however,

that modifications thereof falling within the scope of the appended claims will be apparent to persons skilled in the art.

The method disclosed herein is being claimed in the applicants copending application filed on April 22, 1942.

I claim:

1. A generally cylindrical form for concrete pipes, said form having a plurality of longitudinal rows of spaced apertures, a bar disposed 10ngitudinally of the form and overlying each row of apertures, a plurality of pins fixedly carried by said bar and extending into said apertures, guide means for said bars, spring means disposed between each bar and the outer face of the form, and cam devices carried by the guide means, whereby manipulation of the cam will cause said pins to project interiorly of the form and release of the cam will cause said pins to be retracted by said spring means.

2. A generally cylindrical form for concrete pipes, said form having a plurality of longitudinal rows of spaced apertures, a yoke fixedly mounted on the exterior face of said form between a pair of adjacent apertures in each row approximately midway of the length of the section, a manually operable cam device pivotally mounted in said yoke and spaced from the outer face of the form, a bar disposed within the yoke between the cam and section longitudinally of the form and overlying said row of apertures, a plurality of pins fixedly carried by said bar and extending into said apertures, and spring means disposed between each bar and the outer face of the form, whereby manipulation of the cam will cause said pins to project interiorly of the form and release of the cam will cause said pins to be retracted by said spring means.

3. A generally cylindrical form for concrete pipes, said form having a plurality of longitudi- :nal rows of spaced apertures, a yoke fixedly mounted on the exterior face of said form between a pair of adjacent apertures in each row, a manually operable cam device pivotally mounted in said yoke and spaced from the outer face of the form, a rigid metal bar disposed within the yoke between the cam and form longitudi- 1 nally of the form and overlying said row of apersome of said pins being threaded, and stop nuts carried by the threaded pins, whereby manipulation of the cam will cause said pins to project interiorly of the form and release of the cam will cause said pins to be retracted by said spring means.

i. A form for concrete pipes, said form comprising a plurality of longitudinal sections, one of said sections having a plurality of longitudinal rows of spaced apertures, a yoke fixedly mounted on the exterior face of said sections between a pair of adjacent apertures approximately midway of the length of the section, a manually operable cam device pivotally mounted in said yoke and spaced from the outer face of the form, a bar disposed within the yoke between the cam and section longitudinally of the section and overlying said row of apertures, a plurality of pins fixedly carried by said bar and extending into said apertures, and helical springs surrounding some of said pins between the bar and the outer face of the section, whereby manipulation of the cam will cause said pins to project interiorly of the form and release of. the cam will cause said pins to be retracted by said springs.

5. A form for concrete pipes, said form comprising a plurality of longitudinal sections, one of said sections having a plurality of longitudinal rows of spaced apertures, a yoke fixedly mounted on the exterior face of said sections between a pair of adjacent apertures approximately midway of the length of the section, a manually operable cam device pivotally mounted in said yoke and spaced from the outer face of the form, a rigid metal bar disposed within the yoke between the cam and section longitudinally of the section and overlying said row of apertures, a plurality of pins fixedly carried by said bar and extending into said apertures, helical springs surrounding some of said pins between the bar and the outer face of the section, the end pins being threaded, and stop nuts carried by said end pins, whereby manipulation of the cam will cause said pins to project interiorly of the form and release of the cam will cause said pins to be retracted by said springs.

6. A form for concrete pipes, said form comprising a plurality of transversely corrugated longitudinal sections, one of said sections having a plurality of longitudinal rows of spaced apertures in the crowns of said corrugations, a yoke fixedly mounted on the exterior face of said sections between a pair of adjacent apertures, approximately midway of the length of the section, a manually operable cam device pivotally mounted in said yoke and spaced from the outer face of the form, a rigid metal bar disposed Within the yoke between the cam and section longitudinally of the section and overlying said row of apertures, a plurality of pins fixedly carried by said bar and extending into said apertures, helical springs surrounding some of said pins between the bar and the outer face of the section, the end pins being threaded, and stop nuts carried by said end pins, whereby the manipulations of the cam will cause said pins to project interiorly of the form for a length substantially equal to the thickness of the wall of the pipe being formed and release of the cam will cause said pins to be retracted by said springs.

EUGENE F. BESPALOW. 

